I'll have to read the book...maybe he makes a clearer argument than in this map, or is selecting on some variable I'm not seeing.
I've also lived in south Georgia (a little over a year) and Seattle (4 years), and have traveled those areas extensively. Those parts of the map definitely ring true to me, especially the "left coast" designation for the PNW (a lot of my friends in Seattle jokingly called it that) and the "New France" designation for the NOLA area.
I'll definitely be checking this book out - thanks for the recommendation.